Sorting User Data by Registration Date
You've been tasked with creating a system to display user data in a clear and organized manner. A common requirement is to present this data based on when users registered. This challenge will test your ability to sort data in ascending and descending order using SQL's ORDER BY clause.
Problem Description
You will be working with a Users table that contains information about registered users. Your goal is to retrieve a list of all users, sorted by their registration_date in both ascending and descending order.
Requirements:
- Retrieve all columns from the
Userstable. - Sort the results in ascending order based on the
registration_datecolumn. - Sort the results in descending order based on the
registration_datecolumn.
Expected Behavior:
When a query is executed, the returned rows should reflect the specified sorting. For ascending order, the oldest registrations should appear first. For descending order, the most recent registrations should appear first.
Edge Cases:
- No users in the table: The queries should return an empty set of results.
- Identical registration dates: If multiple users registered on the same date, their relative order within that date group is not strictly defined by this problem, but it should be consistent. For this challenge, you don't need to worry about secondary sorting criteria for identical dates.
Examples
Example 1: Ascending Order
Assume the Users table contains the following data:
| user_id | username | registration_date | |
|---|---|---|---|
| 1 | alice | alice@example.com | 2023-01-15 |
| 2 | bob | bob@example.com | 2023-03-10 |
| 3 | charlie | c@example.com | 2023-02-20 |
Input: Pseudocode for a SQL query to get all users sorted by registration_date in ascending order.
Output:
| user_id | username | registration_date | |
|---|---|---|---|
| 1 | alice | alice@example.com | 2023-01-15 |
| 3 | charlie | c@example.com | 2023-02-20 |
| 2 | bob | bob@example.com | 2023-03-10 |
Explanation: The Users table is queried, and the results are ordered by registration_date from earliest to latest.
Example 2: Descending Order
Using the same Users table as in Example 1:
| user_id | username | registration_date | |
|---|---|---|---|
| 1 | alice | alice@example.com | 2023-01-15 |
| 2 | bob | bob@example.com | 2023-03-10 |
| 3 | charlie | c@example.com | 2023-02-20 |
Input: Pseudocode for a SQL query to get all users sorted by registration_date in descending order.
Output:
| user_id | username | registration_date | |
|---|---|---|---|
| 2 | bob | bob@example.com | 2023-03-10 |
| 3 | charlie | c@example.com | 2023-02-20 |
| 1 | alice | alice@example.com | 2023-01-15 |
Explanation: The Users table is queried, and the results are ordered by registration_date from latest to earliest.
Constraints
- The
Userstable will always have at least the columnsuser_id,username,email, andregistration_date. - The
registration_datecolumn will be of a date or datetime data type. - The
Userstable can contain between 0 and 10,000 rows. - Your solution should be efficient and perform well for the given table size.
Notes
- The
ORDER BYclause in SQL is used to sort the result set of a query. - By default,
ORDER BYsorts in ascending order (ASC). You can explicitly specifyASCorDESCfor descending order. - Consider how you would structure your queries to achieve both ascending and descending order results separately.